Cochlear implants are very reliable devices, and each manufacturer claims reliability advantages over its competition measured in tenths of a percent. Still, implants are manufactured devices, and the goal of zero defects for the life of the user is admirable, but not likely achievable.
Each month the FDA receives over a hundred reports of problems with cochlear implants. Some of these are medical in nature, and not related to hardware reliability. While all manufacturers are supposed to report every incident to the FDA, compliance is voluntary, and there is no means of enforcement.
A recall occurs when the manufacturer decides to halt production of an implant, and recall all unimplanted devices. This may be due to internal concern over patient safety, or it may be as a result of discussions with the FDA. All cochlear implant recalls have been voluntary, but the FDA seems to allow the manufacturers the discretion to issue a voluntary recall before issuing a compulsory one.
A recall means that the devices which have been shipped to implant centers around the world must be returned to the manufacturer. Devices that have already been implanted are not affected by a recall. Of course, if an implanted device fails, it may have to be removed and replaced.
Companies may choose to fix problems while maintaining production. Even with an identified problem, as long as a recall has not been issued, the company may continue production. Continuous improvement of product quality is certainly admirable. But the decision must always be made whether to allow devices that were manufactured before an improvement is made.
Once a recall has been issued, the company must determine the exact root cause of the failure mechanism. When the cause has been identified, changes must be made to the materials or manufacturing process to ensure that the failure does not occur again. At this point, the FDA is closely involved, and sufficient proof that the issue has been resolved must be submitted to the FDA. It is up to the FDA to determine whether the issue has been completely resolved, and to allow the company to resume production.
Following is a list of past recalls and halts or delays in production of cochlear implants. This list is not an indicator of current quality, as each closed issue has passed the FDA’s stringent requirements for resuming production.
- Cochlear, CI500 series, 2011: Hermeticity failure. Moisture enters the implant, eventually causing an electrical failure in some cases.
- Advanced Bionics, HiRes90k, 2010: Latent short circuit in substrate, 2 devices affected. Substrate thickness increased to prevent short circuits.
- Advanced Bionics, HiRes90k, 2006: Hermeticity failure. Hermetic seals created by one of two specialty manufacturing companies (Vendor B) experienced a latent failure. Moisture entered the implant, eventually causing an electrical failure in some cases. Manufacturing process control implemented. Vendor A devices not affected.
- Advanced Bionics, HiRes90k, 2004: Moisture trapped inside of implant at time of manufacture. Manufacturing process control implemented.
- Advanced Bionics CII, 2002: Suspicion of electrode array positioner being correlated to risk of meningitis. Implant was recalled and subsequently resumed production without the positioner.
- Advanced Bionics 1.0, 1995: Cracked ceramic cases. Case design strength increased.
- Cochlear, 1995: Internal power supply failure, capacitors installed backwards. <10 devices explanted.